In applicant's U.S. Pat. Nos. 4,397,809 and 4,397,810 an atomic fusion process is disclosed wherein two oppositely directed streams of ions are forced to follow the same spiral paths in the same reaction zone for promoting fusion producing collisions between particles of one stream and particles of the other stream. By way of example, the streams may comprise deuterium and helium 3 ions, respectively.
The reaction zone comprises an annulus between an inner cylindrical electrode and an outer cylinderical electrode between which a radial electric field is established to control and maintain the streams in the spiral path.
Where two such beams of positively charged particles move in opposite directions along such spiral path, the statistical effect of multiple coulomb scattering may produce waves of plasma-density and/or plasma boundary position. Under some conditions, such waves may have amplifying or growing properties. Growing or amplified waves can reach amplitudes which allow the particle beams to break out of the constraints provided by the system, and so lose fuel and energy from the reactor. For certain fuel combinations, the nuclear cross sections are undesirably small compared to the statistical coulomb scattering cross section. As a result, scattering waves, if not controlled or damped out, could prevent efficient operation of the reactor. If is therefore desirable to provide a damping system to prevent the occurrence and/or growth of such waves at their possible inception.